This study will investigate the induction of aryl hydrocarbon hydroxylase (AHH) in mitogen-activated peripheral blood lymphocytes, in pulmonary alveolar macrophages obtained by saline lavage, and in surgically resected lung tissue. For lymphocytes, inducibility of AHH will be compared with other measures of lymphocyte function, including lymphoproliferative responses to soluble antigens. The metabolites of selected polycyclic aromatic hydrocarbons will be examined for cigarette smoking and non-smoking patients, with and without primary lung cancer.